Method of reclaiming detergent solutions



Feb. 9, 1954- F. w. WEHMILLER ET AL ,6

METHOD OF RECLAIMING DETERGENT SOLUTIONS Filed Oct. 17, 1949 CLEANS NG ZONE FROTHY DETERGENT 5OLUT\ON CQNTIMNING SQLID FORE-6N MATERIAL soup FORElGN MATERIAL DE.5CEND\N6 FROM CLEANSiNG ZONE INCLUDING UQUEHED FOAM Ill ll r INVENTORS FREDEVHCK W. WEHMlLLER WILLJAM d- NEKOLA alum wem ATTORNEY.

all

Patented Feb. 9, 1954 METHOD OF, RECLAIMING DETERGEN'L SOLUTIONS:

Frederick; Wehmill'er, Ladile; and'Willia/im-Ji Nekolag Normandy;'.Mo., assignorsa to Barry!- WehmillerrMachinery CompanySts-Louis; Mum alcorporationsofiMissouri Appiicatiolr October-17, 1949; SerialNo; 121308;

2 GlaimSa, (Cl. Zine-2;)

This invention relates to methods of -reclaiming detergent solutions, and particularly to the problem of" reclaiming -suchs0lutions" th'athave been 1 used under conditions which produce large volumes of'foam. Forexample, foaming occurs when a detergent solution is forcibly employed for cleansing operations, especially when the solution is: forcibly: projected from nozzles In somecasesthe foaming ismaterially increased by; the -presenceof paper; glue, etc.

Arrobjectof theinvention is to -provide a commercially desirable method i whereby foam: bubbles are converted into free liquid while a stream of "i the =used foamy detergent solution is flowing through a simplereclaiming station;

further 'ohject is to produce a continuous process of 'this kind whereinsolid foreign matter is removed from the solution during the step of converting foam into free liquid:

An old problemthis art appears in the disposal of foamy caustic solutions fiowing from an elaborate cleansing system wherein numerous small streams of caustic solution are forcibly projected onto-traveling bottles; or other articles;

so -as t'o remove-:labels and otherwise cleanse the Sol-utions of thiskind will foam in re'-- sponse to' agitationaso the forcible treams alonewill' result: in very-:- violent foaming, whichis in-- creasedby subsequent splashing of the falling-- articles.

liquid; and also by the presence of glue and paper in -the labels' forcihly removed from the t'raveling articles;

in a continuous heterogeneous stream;

A specific obj ect' of the present invention; is to immediately subject the foamystream to acontinuous reclaiming operation while it fallingfrom a cleansing zone-, thereby eliminating some tions" whereby interrupted foam bubbles are" broken, or merged intoeach other and converted into'free' liquid; which descends with said liquid portions of 'the falling stream; while the 1 inter-- rupted solid foreigntmaterial travels away from the liquid stream.

In this-manner; the-verylarge froth'y mass is immediately converted into i a relatively small Iiiactualcommercial' practice, the re sultant used solution 'is a voluminous frothymass containing solid foreign material such as paper labels;- orfragments of labels; brokemglass; andothen'solidg particles, all' of which are discharged" 2; stream of recl'aimed solution that can be readily delivered toa storage receptacle, while solid? foreign matteris withdrawn and separated -from' the falling liquid-solution;

With the 1 foregoing and otherobjectsinview,"

" the invention comprises the novel method here thereby interrupting a mass of foam and solidi:

foreignmater-ial at the screen; while allowing liquid portions of "the falling stream to freely de'fiscenzithrough the-screen; This screen is suba jected-toa-rapid vibr-atory motion, which isrim parted to the interrupted mass: of foam; with theresult of breaking the yieldable'body'of foam and causing foam bubbles to merge into each other; thereby convertingfoam. into free liquid; which readil'y fallsthrough the screen. The in'e" terrupted solid foreign material is also subjected to vibrations of thescreen, whichcause this solid material to travel away from thevibratingmasa of interrupted foam, and thereby separate framev the falling stream of "reclaimedsolution;

To illustrate a simple apparatus: we have; shown a screen 3 provided with a frame including: side wall members flit and an endiwall member: 5. This screen i is yieldahly supported by a pair: of?" elongated leaf;springs 6, each having a middle; portion rigidly secured to astationarylsbracket I; and free upper: end" portions 8? attached tonnes ofthe side wallmemhers However, the screen; can be yieldably supported and vibrated in. any suitable manner.

A's a-simple means :for impartingsairapid vibrant:- tory motion to the screen, we have shown aa-tua bulan housing 9*- located above the screen and having: its ends 1 rigidly secured a to Y the? sideswalli members. This housing contains :a': rotary; shafts having'an eccentric: portion Illiforming; an une balanced weight and trunnions l l extending from; said weight, said" trunnions being: supportedr in suitable bearings at end? portions :of: the: housing 9. A- driving pulley! 2 ins-secured toioneroffthesw trunnions- H to-providefor rotation of? the ec'a centric=weights It will be observed that the housing 9 and its eccentric shaft are supported by the side wall members 4 of the screen frame which rest upon the free upper ends of the springs 6. As a consequence, the screen will vibrate in response to rotary movements of the eccentric weight 10, which whirls around the axis of the trunnions ll without touching the housing 9. Extremely rapid vibrations can be produced by turning the eccentric shaft at high speeds, so as to rapidly vibrate the screen in more or less circular cycles. For example, a speed of about 2000 revolutions per minute will produce effective rapid vibrations, but any other desirable high speed can be employed.

The drawings illustrate a system wherein the new method has been very advantageously used on a large commercial scale to recover caustic solution while it is falling from a cleansing zone. Numerous streams of the solution are discharged onto and into traveling bottles at the cleansing zone, so as to remove labels, glue, etc. As previously indicated, extremely violent foaming occurs at the numerous streams which forcibly contact with the bottles and splash onto portions of the bottle carriers, and finally fall with additional splashing to a large discharge opening. The foaming is increased by the presence of paper and glue in the violently agitated solution, so the outgoing stream is a voluminous frothy mass, that has been difficult to control after it leaves the cleansing zone.

Instead of trying to transmit the ingredients of this continuous stream to storage, we cause the falling mixture to drop through a large spout I3 to an end portion of the vibrating screen 3. The free liquid portions of the solution readily descend through the screen, but the mass of foam is interrupted at the screen where it is confined by the side and end walls 4 and 5 of the screen frame. The additional free liquid resulting from vibration of the foam bubbles, will readily descend through the screen and form part of the reclaimed solution.

As a detail of the new method, we maintain a pool M of reclaimed solution in a plane lower than the vibrating screen 3, and we preferably direct the recovered solution falling from the screen through a slightly inclined elongated downward course, at a relatively low velocity, along the baffle plates I5 and IE, to the top surface of the pool l4, so as to avoid excessive agitation of the recovered solution. This tends to increase the yield of liquid in the reclaimed solution.

Furthermore, our reclaiming operations can be performed while the continuous stream is descending by gravity from a cleansing zone, without using pumps or other mechanical transferring devices that would forcibly agitate the solution and thereby cause additional foaming. The new process very conveniently eliminates large volumes of foam and greatly reduces the problem of handling and reclaiming the bulky stream.

The interrupted mixture of paper and other solid foreign material travels along the vibrating screen to the open end I! of the screen frame, where it is separately discharged from the system.

Important commercial advantages of the new method appear in the simplicity and low cost of the reclaiming operations, and also in the real value of conveniently reducing the voluminous frothy mixture while the used solution is falling 4 from a cleansing zone to a pool of recovered solution.

An example of a detergent solution actually used in the removal of labels, etc. from traveling bottles, consists of a 4% solution of sodium hydroxide, known as a caustic solution, which may be modified by the addition of sodium carbonate, trisodium phosphate as well as other organic or inorganic agents tending to increase the detergent powers of the solution. However, it is to be understood that advantages of the invention can be obtained in the reclaiming of other detergent solutions which produce large volumes of foam in response to violent agitation in a cleansing zone. The strokes of the rapid vibrations of the screen are very short, and may be about 3 2' of an inch, or even less. A screen having a mesh between 12 and 20 per inch is satisfactory.

We claim:

1. The method of reclaiming the liquids held in a bubble-like suspension of a frothy mass in caustic solution, containing paper and other solid materials, which comprises directing all of the liquid, frothy mass of suspended liquid and solid material in a free falling stream, interrupting the solids and frothy mass of the stream while allowing the liquid portions of the stream to pass on in the same direction as the free falling stream, breaking down the interrupted frothy mass to separate the liquid portion from the solids and release the air and other gases entrapped therein and simultaneously progressively displacing the interrupted solids from the free falling stream, collecting below the point of interruption of the solids and frothy mass the liquid portions of the stream, including the separated liquid portion of the frothy mass, and directing the collected liquid into a pool at a relatively low velocity to avoid frothing of the reclaimed solution.

2. The method of reclaiming the liquids held in a bubble-like suspension of a frothy mass in a caustic solution, containing paper and other solid materials, which comprises directing all of the liquid, frothy mass of suspended liquid and solid material in a free falling stream, interrupting the solids and frothy mass of the stream while allowing the liquid portions of the stream to pass on in the same direction as the free falling stream, vibrating the interrupted frothy mass and solids to displace the solids from the stream and simultaneously convert the frothy mass to free liquid, collecting below the level at which interruption occurs only the liquid portions of the stream, including the separated liquid portion of the frothy mass, and running off the collecting liquid into a pool at a relatively low velocity to avoid frothing of the reclaimed solution in the pool.

FREDERICK W. WEI-INIILLER. WILLIAM J. NEKOLA.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,805,830 Mason May 19, 1931 2,183,896 Rupp et al. Dec. 19, 1939 2,329,333 Carter Sept. 14, 1943 2,421,952 Lipsius June 10, 1947 OTHER REFERENCES Flotation by Gaudin, pub. 1932, by McGraw- Hill Book Co Inc., N. Y. page 69 cited. 

1. THE METHOD OF RECLAIMING THE LIQUIDS HELD IN A BUBBLE-LIKE SUSPENSION OF A FROTHY MASS IN CAUSTIC SOLUTION, CONTAINING PAPER AND OTHER SOLID MATERIALS, WHICH COMPRISES DIRECTING ALL OF THE LIQUID, FROTHY MASS OF SUSPENDED LIQUID AND SOLID MATERIAL IN A FREE FALLING STREAM INTERRUPTING THE SOLIDS AND FROTHY MASS OF THE STREAM WHILE ALLOWING THE LIQUID PORTIONS OF THE STREAM TO PASS ON IN THE SAME DIRECTION AS THE FREE FALLING STREAM, BREAKING DOWN THE INTERRUPTED FROTHY MASS TO SEPARATE THE LIQUID PORTION FROM THE SOLIDS AND RELEASE THE AIR AND OTHER GASES ENTRAPPED THEREIN AND SIMULTANEOUSLY PROGRESSIVELY DISPLACING THE INTERRUPTED SOLIDS FROM THE FREE FALLING STREAM, COLLECTION BELOW THE POINT OF IN- 